A disposable diaper such as a so-called tape-type diaper or an underpants-shaped disposable diaper is conventionally known as an absorbent article for absorbing excrement. These tape-type diapers and underpants-shaped disposable diapers have a problem of difficulty in being put on a wriggling infant and a problem that the diapers force a wearer to take an unnatural posture when being put on. In order to solve these problems, PTL 1 describes a disposable diaper 1 in which portions on either one side of the left or right sides of the waist part are joined together, and portions on the other side are not joined together.